By Paul Homewood
Further to the BBC article on Storm Darragh, just posted, it is worth pointing out that ABI, the Association of British Insurers, also talk of 55 mph gusts:
Storms
Windstorm is the most damaging of the natural perils covered by property insurers. During major windstorm events the damage can be substantial – considerable losses occur every year in the UK.
A storm is a period of violent weather defined as:
- Wind speeds with gusts of at least 48 knots (55mph)* or;
- Torrential rainfall at a rate of at least 25mm per hour or;
- Snow to a depth of at least one foot (30 cm) in 24 hours or;
- Hail of such intensity that it causes damage to hard surfaces or breaks glass
*Equivalent to Storm Force 10 on the Beaufort Scale.
https://www.abi.org.uk/products-and-issues/topics-and-issues/flooding/storms/
Now, they may well intend that gusts of 55 mph is their definition of a storm. But if so, they are quite wrong in saying it is equivalent to Storm Force 10.
The Royal Meteorological Society are absolutely clear that the Beaufort Scale is measured from mean wind speeds, not gusts:
https://www.rmets.org/metmatters/beaufort-wind-scale
I have asked the ABI to clarify. It is after all a matter of serious import to insurance companies and customers.